1. Field of the Invention
The invention relates to a process for preparing organosilanes from hydrosilanes and halohydrocarbons in the presence of a free-radical initiator.
2. Background Art
Processes are known in which the hydrogen in hydrosilanes is replaced by a hydrocarbon radical. The thermally induced reaction of hydrosilanes with halohydrocarbons, and also the reaction in the presence of catalysts, are described, for example, in: ORGANOHALOSILANES, by R. J. H. Voorhoeve, Elsevier Publishing Company 1967, pages 40–48.
Thermal initiation has greater significance in the preparation of phenyltrichlorosilane or phenylmethyldichlorosilane from chlorobenzene and trichlorosilane or dichloromethylsilane. Disadvantageously, lower conversions are obtained in this process at low temperatures and a high proportion of undesired by-products at high temperatures. Phenyltrichlorosilane and phenylmethyldichlorosilane are used to prepare organopolysiloxanes.
DE 2132569 A discloses that these reactions can be initiated by appropriate wavelengths of electromagnetic radiation.
Chem. Abstr. 84: 44 345e further discloses the preparation of organochlorosilanes by reacting chlorine-containing aromatics with hydro- or organohydrochlorosilanes employing hexachlorodisilane as a catalyst. Disadvantageously, the preparation of hexachlorodisilane is costly and inconvenient.